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Mexican-American War

Mexican-American War


The Mexican-American War commenced on May 13, 1846, after President James Knox Polk (17951849) pressured Congress for an immediate declaration of war on Mexico. The road to war with Mexico represents a complicated period in U.S. history. By late 1845 political upheaval between the Whigs and the Democrats had reached a crescendo in Congress. The most pressing political issue surrounding war with Mexico had been the potential expansion of slavery to the U.S. Southwest. Many prowar congressional leaders favored battle as a means by which they could increase the influence and lucrative potential of slavery; meanwhile other hawkish war supporters understood the conflict to be a moral struggle for the purpose of spreading freedom and liberty in the absence of servitude. Former president John Quincy Adams (18251829), an ardent antislavery advocate, became one of the few voices of dissent in the House of Representatives then dominated by congressmen arguing for war.

By 1803 Texas had become a disputed territory between the United States and Mexico. Many Americans loudly proclaimed Texas a part of the Louisiana Purchase brokered by President Thomas Jefferson on April 30, 1803. In 1821 Mexico achieved independence from Spanish control. Most of the Spanish leaders, pejoratively labeled gachupines, were deposed, and in their place native mestizo rulers assumed control of the government. (Gachupines were native Spaniards who oppressed, enslaved, and exploited indigenous Mexicans. This is a pejorative term referring to Spanish imperialists, similar to the word gringo.) The mestizos became known as criollos, most of whom demonstrated ineptitude due to their initial inexperience at governing, for under Spanish rule few indigenous citizens had achieved positions of power (Faulk and Stout 1973, p. xiii). Political turmoil and chronic factionalism followed the Mexican independence movement. Approximately thirty-six changes in leadership occurred between 1833 and 1855. The military remained dominant in political affairs, a circumstance that facilitated the rise of Mexican general turned president Antonio López de Santa Anna (17941876), who was elected president of Mexico by a majority vote in 1833. Santa Anna began his military career in 1810 as a cadet under the command of Joaquín de Arredondo. Mexican historians differ on whether he was vulgar and corrupt or a brave and skillful leader.

Provoked by the aggressive movements of volunteer soldiers from Texas in 1836, the fiery Santa Anna set his sights on attacking Texan forces garrisoned at the Alamo mission in San Antonio. A bloody battle ensued at the Alamo. The most popular American interpretation of this incident depicts a small but death-defying American force of roughly three hundred soldiers led by Sam Houston and Davy Crockett pitted against Santa Annas roughly eight thousand bloodthirsty attackers (Mexican historians present a significantly different version of the battle). The battle officially lasted for thirteen days, from February 23 to March 6, 1836. There is some debate as to whether the Mexican general ordered the execution of American forces surrendering peacefully or if the Americans chose to fight until the bitter conclusion. The undeniable historical result of this tragic event is that no Americans were left alive. Consequently Santa Anna became a virtual public enemy in the United States.

While the battle raged at the Alamo, a group of sixty councilmen representing the U.S. citizens of Texas gathered at the General Convention in the town of Washington and unanimously declared independence. All sixty signatories to the Texas Declaration of Independence (March 2, 1836), including Sam Houston, declared their independence from the evil rulers who brought oppression and removed even the semblance of freedom.

Compassion among U.S. observers of the Texans struggle further developed because of Mexicos Goliad campaign of 1836 (also referred to as the Goliad massacre). This event has taken second place to the Alamo in American memory. One of Santa Annas commanders, General José de Urrea (17951848), succeeded in taking prisoner 230 American soldiers who surrendered voluntarily on March 20, 1846. Santa Anna betrayed Urreas promise of their safety by ordering the execution of many of the unarmed Texas fighters. Their deaths were justified by Santa Anna, who labeled them foreign pirates who had attacked a sovereign government without legal cause (Faulk and Stout 1973, p. xv).

At the battle of San Jacinto on April 21, 1836, Santa Annas forces suffered defeat at the hands of an outraged Texan army. Santa Anna sought to avoid capture and punishment by dressing in plain clothing and hiding in the fields. Eventually U.S. forces recognized and seized him.

This battle for all intents and purposes secured Texan independence and halted Santa Annas onslaught. In 1836 Anglo-Americans residing in Texas declared independence. Mexican leaders immediately recognized the danger in the United States receiving an unfettered pass to annex the former Mexican territory. Many feared the U.S. spirit of expansion would whet the appetite of expansionists in Congress and expedite the annexation movement.

Meanwhile, in order for Mexican leaders to maintain power, they had to continually promise embittered constituents a reconquest of Texas. Mexico refused to acknowledge Texas as an independent state and asserted both its claims to the disputed territory and its willingness to defend against U.S. violation of its sovereignty. Nevertheless, the U.S. government did not express an absolute commitment to sending military forces to defend Texas against an onslaught. This prompted volunteer soldiers, also known as soldiers of fortune, to flood into the disputed region (Haynes 2002, p. 115). Despite promises to recover San Antonio and other lost territories, Mexicos promised assaults failed to materialize. In early 1845 the voters of Texas approved the Annexation Ordinance, which prompted a congressional authorization known as the Joint Resolution to Admit Texas as a State; this was subsequently signed into effect by President Polk on December 29, 1845. Northern abolitionists feared that the admittance of Texas into the Union would encourage the expansion of slavery and destabilize the nation. John R. Collins writes that a small group of Whig abolitionists viewed the war as a slavocracy conspiracy (Faulk and Stout 1973, p. 70).

Born in Mecklenburg County, North Carolina, in 1795, Polk became president of the United States in 1844. His political platform consisted primarily of a belligerent attitude toward Mexicos reluctance to relinquish the southwestern territories and an aggressive stance toward Great Britain, who refused to budge on the issue of sharing or relinquishing the Oregon Territory. As a candidate for president, Polk had promised both to reannex Texas and to occupy Oregon from the California boundary to the 54'40 latitudinal line. At this time the theory of manifest destiny was on the rise. The term, coined by the influential Democratic writer and strategist John L. OSullivan, addressed the right of the United States to spread freedom and liberty across the North American continent. Supporters of this ideology believed that God, or divine Providence, had empowered the American people with the ability to conquer the continent and thereby civilize and Christianize the world. Although not completely materialized by 1844, the spirit of manifest destiny, teamed with Polks campaign promises, seemingly offered a mandate to the incipient president to engage those who stood in Americas pathway to continental dominance.

The United States persisted in its assertion that the Rio Grande represented the legal southern border of Texas, despite the obvious lack of evidence to validate the claim. Polk dispatched minister plenipotentiary John Slidell (17931871) to Mexico with the express purpose of settling the border dispute in favor of the Rio Grande rather than the Nueces River, as demanded by the Mexican government. Slidell was also instructed to purchase New Mexico and California. At least two previous presidential administrations, those of John Quincy Adams and Andrew Jackson, had sent negotiators to purchase Texas and possibly the surrounding territories from Mexico; their offers were soundly rejected and seemed only to antagonize Mexican leaders. Polk offered $5 million to redraw the boundary of Texas to the Rio Grande and $25 million for the California Territory. The Mexican government repudiated Slidell and the offer. Consequently President Polk decided to station General Zachary Taylor (17841850) with U.S. forces along the Rio Grande. In turn Mexican general Mariano Arista (18021855) guarded the Mexican side of the river. Border provocations on April 24 and the refusal of the Mexican government to negotiate with the presidents ambassador instigated war. After President Polk delivered a war message to Congress, the United States officially declared war on Mexico on May 13, 1846.

Combat had already commenced, with Colonel Stephen Kearnys Army of the West traveling to New Mexico and then to California to secure those territories for U.S. migration and General Zachary Taylors army crushing the Mexican forces in battles at Palo Alto and Resaca de Palma. Kearny fully controlled Santa Fe by August 18, 1846. In California a group of American settlers, along with an exploring party led by John C. Frémont (18131890), joined Kearny in what became known as the Bear Flag Revolution (Brinkley 2003, p. 352). U.S. soldiers experimented with flying artillery at Palo Alto, and hand-to-hand fighting erupted at Resaca de Palma. The U.S. Navy seized control of Monterey and Los Angeles thanks to Commodore John Drake Sloat (17811867). During these tempestuous days of battle, the former Mexican general Santa Anna returned from exile to prepare an army of roughly twenty thousand men with the express purpose of fighting the invaders until any defense would become untenable. Enthusiasm for war in the United States led to 200,000 volunteers responding to the secretary of wars call to arms (Haynes 2002, p. 155).

U.S. forces entered battle outnumbered in almost every engagement with Mexico (Eisenhower 1986, p. 35). The most recognizable casualties of war were Henry Clay, Jr., and Archibald Yell, former governor of Arkansas (both at Buena Vista), and Captain Samuel Walker of the Texas Rangers, at Huamantia (Eisenhower 1986, p. 36). Volunteer forces received only a rudimentary training, and due to the sporadic popularity of the war, many of the soldiers, themselves from different states, never trained together. Many of the volunteers were not supplied with the bare essentials, and this led to sickness and disease. Statistically the greatest challenge to the army, and the most damage inflicted on it, was caused by outbreaks of disease. Of the approximately 100,182 soldiers who fought in the war, nearly 10,790 died from disease and exposure to inclement weather. A much smaller number, 1,548 volunteers, died on the battlefield. Generals George B. McClellan (18261885) and Winfield Scott (17861866) marveled at the destruction wrought on their forces by rampant diseases. The historian Thomas Irey asserts that nearly 10 percent of all noncombat deaths were caused by disease and infection (Faulk and Stout 1973, p. 110). President Polks troubled relationships with generals Scott and Taylor further challenged the U.S. militarys already troubled tactics (Haynes 2002, p. 152). On November 19, 1846, the president reap-pointed General Scott commander of the army, displacing Taylor.

On March 9, 1847, General Scott landed at Veracruz with ten thousand soldiers, finally entering Mexican territory to compel surrender. Scott eventually advanced 260 miles across the Mexican National Highway to Mexico City. This major amphibious assault was the first of its kind in U.S. history (Brinkley 2003, p. 352). On April 18 Scotts forces pushed forward at Cerro Gordo, flanking Santa Annas forces and forcing his retreat, embarrassingly without his artificial leg. Some of the most famous future Civil War generals planned this mission, including Robert E. Lee (18071870), McClellan, Joseph E. Johnston (18071891), and P. G. T. Beauregard (18181893). At Churubusco on August 20, Scotts army defeated a Mexican defensive force of twenty thousand soldiers. The last major confrontation before Scotts forces marched on Mexico City was the battle of Molino del Rey, in which twelve thousand Mexican soldiers lost the battle and the overall struggle and Scott took Chapultepec, overlooking Mexico City. Nevertheless, by September 1847 many Americans had become frustrated by Mexicos refusal to accept terms of surrender (Davis 1999, p. 316).

In the summer of 1847 Mexico received Polks special peace envoy Nicholas P. Trist (18001874). In July, Mexico stalled, then rebuffed the ambassadors offer. Although Polk recalled Trist and sought to demand more from Mexico, on February 2, 1848, the Treaty of Guadalupe Hidalgo was negotiated by the envoy. The treaty ceded to the United States 500,000 miles of Mexican territory that would become the U.S. states of New Mexico, California, Arizona, Nevada, Wyoming, and Colorado (Davis 2003, p. 192). Mexico also conceded that the Rio Grande would become the permanent border of Texas. The United States compensated Mexico with $15 million in exchange for the lost territory and $3.25 million in remuneration. The Senate ratified the treaty by a vote of 38 to 14 on March 10, 1848 (National Archives 2003, p. 72).

More so than the Mexican-American War itself, the events that roused the bellicose passions of the American people have been captured in cinematic history. Walt Disney produced a three-episode television series about Davy Crockett that included Davy Crockett at the Alamo (1955), a romantic story depicting a group of outnumbered Americans surrounded by a marauding army waiting to pummel them. There also have been more than twenty major motion pictures produced about Crocketts famous execution after or death in battle at the Alamo. In 1960 John Wayne directed and starred as Crockett in The Alamo. In 2004 Billy Bob Thornton starred as Crockett in another film titled The Alamo alongside Dennis Quaid, who was cast as General Sam Houston. Most of the films on this subject depict a mythologized version of historical events.

Many political theorists point to U.S. imperialism and the insatiable southern drive to further the institution of slavery as the motivations for war with Mexico. Utilizing the writings of the then-congressman Abraham Lincoln, some political scientists assert that Mexican provocations led to the shedding of American blood to be sure but on the Mexican side of the border, thus negating the American claim that Mexico had trespassed on U.S. soil illegally, prompting the U.S. declaration of war. More traditional historians assert that the Mexican leadership believed their nation to be omnipotent because of their enormous success in expelling the Spanish leadership and that, given Britains inclination to stir up trouble in the region in order to attain California and to retain the Oregon territories, Mexican leaders felt assured of their assistance should their own forces suffer serious setbacks. The British never offered such assistance.

According to the historian Kyle Ward, who examines changes in the content of textbooks on U.S. history, late-twentieth-century American political scientists portrayed the U.S. South in a detestable light, alleging that a plot existed to encompass all of Mexicos territory into their slavocracy (Ward 2006, p. 158). Following this line of logic, many historians believe that President Polk and his cohorts would have seized more territory and imposed a harsher indemnity on Mexico if there had not been such widespread domestic and congressional opposition to his policy of expansion. This is why, according to some, Polk never requested a straightforward yes or no vote on the war (Silverstone 2004, p. 198). In lieu of an up-or-down vote, the president asked for reinforcements and war materials for a war that had already been provoked and threatened to engulf the U.S. territory if Congress failed to act quickly and decisively.


Brinkley, Alan. 2003. American History: A Survey. Boston: McGraw-Hill.

Davis, Kenneth C. 2003. Dont Know Much about History. New York: HarperCollins.

Davis, Paul K. 1999. 100 Decisive Battles from Ancient Times to the Present. New York: Oxford University Press.

Eisenhower, John S. D. 1986. Polk and His Generals. In Essays on the Mexican War, ed. Douglas W. Richmond, John S. D. Eisenhower, Miguel E. Soto, and Wayne Cutler, 3465. College Station: Texas A&M Press.

Faulk, Odie B., and Joseph A. Stout Jr. 1973. The Mexican War: Changing Interpretations. Chicago: Sage.

Haynes, Sam W. 2002. James K. Polk and the Expansionist Impulse. New York: Longman.

National Archives. 2003. Our Documents: 100 Milestone Documents from the National Archives. Foreword by Michael Beschloss. New York: Oxford University Press.

Silverstone, Scott A. 2004. Divided Union: The Politics of War in the Early American Republic. Ithaca, NY: Cornell University Press.

Ward, Kyle. 2006. History in the Making: An Absorbing Look at How American History Has Changed in the Telling over the Last 200 Years. New York: New Press.

Jonathan A. Jacobs

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"Mexican-American War." International Encyclopedia of the Social Sciences. . 14 Dec. 2017 <>.

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Mexican-American War


MEXICAN-AMERICAN WAR (1846–1848). The war's remote causes included diplomatic indiscretions during the first decade of American-Mexican relations, as well as the effects of the Mexican revolutions, during which American citizens suffered physical injury and property losses. Its more immediate cause was the annexation of Texas. The Mexican government refused to recognize Texas as independent or the Rio Grande as an international boundary. It first withdrew its minister from Washington, D.C., and then severed diplomatic relations in March 1845.

President James K. Polk anticipated military action and sent Brigadier General Zachary Taylor with his force from Louisiana to the Nueces River in Texas, but he also sought a diplomatic solution. Recognizing that the chief aim of American foreign policy was the annexation of California, Polk planned to connect with that policy the adjustment of all difficulties with Mexico, including the dispute over jurisdiction in the territory between the Nueces River and the Rio Grande.

In September 1845, assured through a confidential agent that the new Mexican government of José Joaquín Herrera would welcome an American minister, and acting on the suggestion of Secretary of State James Buchanan, Polk appointed John Slidell as envoy-minister on a secret mission to secure California and New Mexico for $15 million to $20 million if possible, or for $40 million if necessary—terms later changed by secret instructions to $5 million for New Mexico and $25 million for California.

Mexico refused to reopen diplomatic relations. In January 1846, after the first news that the Mexican government, under various pretexts, had refused to receive Slidell, partly on the ground that questions of boundary and claims should be separated, Polk ordered Taylor to advance from Corpus Christi, Texas, to the Rio Grande, resulting shortly in conflicts with Mexican troops at the battle of Palo Alto on 8 May and the battle of Resaca de la Palma on 9 May. On 11 May, after arrival of news of the Mexican advance across the Rio Grande and the skirmish with Taylor's troops, Polk submitted to Congress a war message stating that war existed and that it was begun by Mexico on American soil. The United States declared war on 13 May, apparently on the ground that such action was justified by the delinquencies, obstinacy, and hostilities of the Mexican government; and Polk proceeded to formulate plans for military and naval operations to advance his goal of obtaining Mexican acceptance of his overtures for peace negotiations.

The military plans included an expedition under Colonel Stephen W. Kearny to New Mexico and from there to California, supplemented by an expedition to Chihuahua; an advance across the Rio Grande into Mexico by troops under Taylor to occupy the neighboring provinces; and a possible later campaign of invasion of the Mexican interior from Veracruz.

In these plans Polk was largely influenced by assurances received in February from Colonel A. J. Atocha, a friend of Antonio López de Santa Anna, then in exile from Mexico, to the effect that the latter, if aided in plans to return from Havana, Cuba, to Mexico, would recover his Mexican leadership and cooperate in a peaceful arrangement to cede Mexican territory to the United States. In June, Polk entered into negotiations with Santa Anna through a brother of Slidell, receiving verification of Atocha's assurances. Polk had already sent a confidential order to Commodore David Conner, who on 16 August permitted Santa Anna to pass through the coast blockade to Veracruz. Having arrived in Mexico, Santa Anna promptly began his program, which resulted in his own quick

restoration to power. He gave no evidences whatever of his professed pacific intentions.

On 3 July 1846 the small expedition under Kearny received orders to go via the Santa Fe Trail from Fort Leavenworth, Kansas, to occupy New Mexico. It reached Santa Fe on 18 August, and a part of the force (300 men) led by Kearny marched to the Pacific at San Diego. From there it arrived at Los Angeles to join the forces led by Commodore Robert Field Stockton, including John Charles Frémont's Bear Flag insurgents. Kearny and Stockton joined forces and defeated the Mexican army at Los Angeles on 8 and 9 January 1847. On 13 January, Frémont and Andres Pico, the leader of the Mexican forces in California, signed the Treaty of Cahuenga. Kearny went on to establish a civil government in California on 1 March.

Taylor's forces, meanwhile, began to cross the Rio Grande to Matamoros on 18 May 1846 and advanced to the strongly fortified city of Monterrey, which after an attack was evacuated by Mexican forces on 28 September. Later, in February 1847 at Buena Vista, Taylor stubbornly resisted and defeated the attack of Santa Anna's Mexican relief expedition.

Soon thereafter the theater of war shifted to Veracruz, from which the direct route to the Mexican capital seemed to present less difficulty than the northern route. In deciding on the campaign from Veracruz to Mexico City, Polk probably was influenced by the news of U.S. occupation of California, which reached him on 1 September 1846. The U.S. Navy had helped secure Monterrey, San Diego, and San Francisco in California and had continued blockades against Veracruz and Tampico. The Navy provided valuable assistance again when General Winfield Scott began a siege of Veracruz. After the capture of the fortress of Veracruz on 29 March 1847, Scott led the army westward via Jalapa to Pueblo, which he entered on 15 May and from which he began his advance to the mountain pass of Cerro Gordo on 7 August.

Coincident with Scott's operations against Veracruz, Polk began new peace negotiations with Mexico through a "profoundly secret mission." On 15 April, Buchanan had sent Nicholas P. Trist as a confidential peace agent to accompany Scott's army. In August, after the battles of Contreras and Churubusco, Trist arranged an armistice through Scott as a preliminary step for a diplomatic conference to discuss peace terms—a conference that began

on 27 August and closed on 7 September by Mexican rejection of the terms offered. Scott promptly resumed his advance. After hard fighting from 7 to 11 September at the battles of Molino del Rey and Chapultepec, he captured Mexico City on 14 September and with his staff entered the palace, over which he hoisted the American flag.

Practically, the war was ended. Santa Anna, after resigning his presidential office, made an unsuccessful attempt to strike at the American garrison Scott had left at Pueblo, but he was driven off and obliged to flee from Mexico.

The chief remaining American problem was to find a government with enough power to negotiate a peace treaty to prevent the danger of American annexation of all Mexico. Fortunately, Trist was still with the army and in close touch with the situation at the captured capital. Although recalled, he determined to assume the responsibility of remaining to renew efforts to conclude a peace treaty even at the risk of disavowal by his government. After some delay, he was able to conclude with the Mexican commissioners a treaty in accord with the instructions that had been annulled by his recall. The chief negotiations were conducted at Mexico City, but the treaty was completed and signed on 2 February 1848 at the neighboring town of Guadalupe Hidalgo. By its terms, which provided for cessation of hostilities, the United States agreed to pay $15 million for New Mexico and California. Polk received the treaty on 19 February and promptly decided to submit it to the Senate, which approved it on 10 March by a vote of thirty-eight to fourteen. Ratifications were exchanged on 30 May 1848.

Among the chief results of the war were expansion of American territory; a new population called Mexican Americans; increased American interest in the problems of the Caribbean and the Pacific and in the opening and control of isthmian interoceanic transit routes at Panama, Nicaragua, and Tehuantepec; and outbursts of "manifest destiny" from 1848 to 1860. The acquisition of Mexico's northern lands also intensified debates over the extension of slavery into new territory and brought the Union a step closer to war.


Connor, Seymour V., and Odie B. Faulk. North America Divided: The Mexican War, 1846–1848. New York: Oxford University Press, 1971.

Johannsen, Robert W. To the Halls of the Montezumas: The Mexican War in the American Imagination. New York: Oxford University Press, 1985.

McCaffrey, James M. Army of Manifest Destiny: The American Soldier in the Mexican War, 18461848. New York: New York University Press, 1992.

Robinson, Cecil, ed. and trans. The View from Chapultepec: Mexican Writers on the Mexican-American War. Tucson: University of Arizona Press, 1989.

Smith, George W., and Charles Judah, eds. Chronicles of the Gringos: The United States Army in the Mexican War, 1846–1848. Albuquerque: University of New Mexico Press, 1968.

J. M.Callahan/f. b.

See alsoHispanic Americans ; Kearny's March to California ; Manifest Destiny ; Navy, United States ; andvol. 9:Memories of the North American Invasion ; Mexican Minister of War's Reply to Manuel de la Peña y Peña ; National Songs, Ballads, and Other Patriotic Poetry, Chiefly Relating to the War of 1846 ; Message on the War with Mexico .

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